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author | Lennart Poettering <lennart@poettering.net> | 2018-03-22 16:53:26 +0100 |
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committer | Lennart Poettering <lennart@poettering.net> | 2018-03-22 20:21:42 +0100 |
commit | ae2a15bc14bc448e625ad93fd044bc077ede4b3f (patch) | |
tree | e503e6cf3b571d0a150dc2cea7d1838f55aaa6ab /src/systemctl | |
parent | 1147eef0b6a5937526247ff81ca1e5e45205ed16 (diff) | |
download | systemd-ae2a15bc14bc448e625ad93fd044bc077ede4b3f.tar.gz |
macro: introduce TAKE_PTR() macro
This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
Diffstat (limited to 'src/systemctl')
-rw-r--r-- | src/systemctl/systemctl.c | 29 |
1 files changed, 11 insertions, 18 deletions
diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c index 064d593131..d23bddc99a 100644 --- a/src/systemctl/systemctl.c +++ b/src/systemctl/systemctl.c @@ -1924,8 +1924,7 @@ static int get_machine_list( return log_oom(); machine_infos[c].is_host = true; - machine_infos[c].name = hn; - hn = NULL; + machine_infos[c].name = TAKE_PTR(hn); (void) get_machine_properties(bus, &machine_infos[c]); c++; @@ -2462,10 +2461,9 @@ static int unit_file_find_path(LookupPaths *lp, const char *unit_name, char **un if (r < 0) return log_error_errno(r, "Failed to access path '%s': %m", path); - if (unit_path) { - *unit_path = lpath; - lpath = NULL; - } + if (unit_path) + *unit_path = TAKE_PTR(lpath); + return 1; } @@ -2497,10 +2495,9 @@ static int unit_find_template_path( if (r < 0) return r; - if (template) { - *template = _template; - _template = NULL; - } + if (template) + *template = TAKE_PTR(_template); + return r; } @@ -6671,8 +6668,7 @@ static int create_edit_temp_file(const char *new_path, const char *original_path } else if (r < 0) return log_error_errno(r, "Failed to create temporary file for \"%s\": %m", new_path); - *ret_tmp_fn = t; - t = NULL; + *ret_tmp_fn = TAKE_PTR(t); return 0; } @@ -6703,12 +6699,9 @@ static int get_file_to_edit( return -EEXIST; } - *ret_path = run; - run = NULL; - } else { - *ret_path = path; - path = NULL; - } + *ret_path = TAKE_PTR(run); + } else + *ret_path = TAKE_PTR(path); return 0; } |